FR2520808A1 - PROCESS FOR FORMING A MIXTURE FOR COMPRESSION INTERNAL COMBUSTION ENGINES OF THE MIXTURE, AND FUEL SUPPLY INSTALLATION FOR CARRYING OUT SAID METHOD - Google Patents

Abstract

A.PROCESS FOR THE FORMATION OF A MIXTURE FOR INTERNAL COMBUSTION ENGINES WITH MIXTURE COMPRESSION, AND FUEL SUPPLY INSTALLATION FOR THE IMPLEMENTATION OF THIS PROCESS. B. CHARACTERIZED IN THAT IT IS PROVIDED, FOR THE FUEL SUPPLY, A FIRST ELEMENT 14 PLACED IMMEDIATELY UPSTREAM OF THE THROTTLE FLAP 7, AND A SECOND FUEL SUPPLY ELEMENT 30 AVAILABLE IMMEDIATELY UPSTREAM OF COMPRESSOR 5, AND THAT THE FUEL SUPPLY IS CARRIED OUT, IN DETERMINED AREAS OF THE OPERATION OF THE INTERNAL COMBUSTION ENGINE, ONLY BY THE FIRST 14; IN OTHER AREAS OF ENGINE OPERATION BY THE FIRST 14, AND THE SECOND 30 ELEMENT; AND IN OTHER AREAS STILL OPERATING, ONLY BY THE SECOND FUEL SUPPLY 30. C. THE INVENTION CONCERNS THE MIXED POWER SUPPLY FOR ENGINES EQUIPPED WITH A TURBO-COMPRESSOR.

Description

Process for the formation of a mixture for engines

  compression internal combustion of the mixture, and

  fuel supply for the implementation of

of this process ".

  The invention relates to a method for forming a mixture for a compression-compression internal combustion engine, comprising a compressor (turbo-compressor) supplying the suction pipe upstream of a choke flap, and supplying fuel

  in the suction pipe according to the characteristics

  operation of this engine and an installation for the fuel supply of combustion engines

  internal compression of the mixture, comprising a compres-

  (turbo-compressor) supplying the suction pipe,

  upstream of a choke flap, the fuel supply

  in the suction pipe according to the

  characteristics of the operation of the engine, in particular

  to link for the execution of the process

  internal combustion, known, supercharged by a turbo-

  compressor and fuel injection, we encounter this disadvantage that the air supplied to the cylinders heats up

  in part, because of the significant compression,

  above 100 O C, which results in a lower

  wise of the cylinder and reduces the efficiency of the engine.

  The process according to the invention is characterized in that there is provided, for the supply of fuel, a first element placed immediately in

  upstream of the choke flap, and a second feed element

  fuel supply disposed immediately upstream of the compressor, and that the fuel supply is realized in specific areas of the operation of the internal combustion engine, only by the first; in other areas of engine operation by the first, and the second element; and in other areas

  still functioning, only by the second element

  fuel supply and the installation is characterized in that it is intended for feeding

  fuel, a first feed element

  immediately upstream of the choke damper, and a second fuel supply element

  immediately upstream of the compressor.

  The process and the installation according to the

  on the other hand, have the advantage that, for the

  provided by the first power supply element

  from the upstream of the choke flap to the various cylinders of the internal combustion engine, there is a relatively long preparation path, which

  strengthens the cooling of the mixture and ensures a better

  their filling of the cylinder, and that the fuel supplied by the second fuel supply element upstream of the compressor, cools, because of its energy consumption during its evaporation, the compressed air and the compressor, so that 'in addition to an extension of the

  lifetime of the compressor, a filling rate

  higher cylinders and an increase in

  which is also based on the significant turbulence and, consequently, on the best distribution of the mixture to

the different cylinders.

  Other improvements and improvements

  of the invention appear from the description which follows

  is particularly advantageous, below the tem-

  operating temperature of the engine and below a

  determined suction pressure which is

  above the full supercharged charge, ie at the beginning of the boost zone, to provide fuel only directly upstream of the choke damper, while above the hose pressure

  predetermined suction, at full load, depending on

  with supercharging, the fuel supply

  should only be done directly upstream of the compres-

  On the other hand, it is advantageous if the load increases

  lie slowly, or even quickly, starting from a

  operating point below the pressure determined

  born from the suction pipe, from the moment oh is

  this determined pressure in the vacuum hose

  to reduce the supply of fuel immediately

  upstream of the choke flap according to a specific function, and to start, in a

  supply of fuel immediately upstream of the com-

  pressure, and to increase it, in such a way that the sum of the quantities of fuel supplied corresponds to the quantity of fuel required. Conversely,

  when the load decreases from a point of operation

  above the pressure in the vacuum hose

  determined ration, to pass, when is reached the

  prescribed pressure in the suction pipe, the supply of

  fuel, according to a specific function, to

  upstream of the compressor upstream of the choke flap.

  The invention will be better understood with regard to

  of the following description of an exemplary embodiment of

  the invention and the accompanying drawings, in which: FIG. 1 shows a fuel supply installation according to the invention with a supercharged engine by a turbo-compressor, FIG. 2 is a graph which shows the quantity of fuel. supplied fuel Q, depending on the pressure p in the suction pipe when the load increases slowly, figure 3 is a graph showing the curve, in time, of the pressure in the suction pipe when the load increases suddenly, Figure 4 is a graph that shows the curve, over time, of the fuel supply

  during a sudden increase in the load.

  In the power supply system

  1, the combustion air passes through a filter 1 in a section 2 of the suction pipe, in which there is a member for measuring the air 3, a

  known type, for example a hot wire mass meter.

  or a meter of the air quantity with check valve

  Next downstream of the air measuring member 3 is a compressor 5 which compresses the quantity of air sucked by an internal combustion engine 4, for example a turbo-compressor of a known type, downstream of which Compressed air arrives in a section 6 of the suction pipe having a choke flap 7 Downstream of this choke flap 7 diverge from the suction pipe 6 of the pipes

  8 which lead to the individual cylinders

  of the internal combustion engine 4 The engine 4 represents

  The four-cylinder engine is a combustion engine, which is a compression ignition system. An exhaust pipe which leads to an exhaust gas turbine 11 which is rigidly coupled with the engine is known as an exhaust pipe.

  compressor 5 and which is driven by the exhaust gas

  hot and strongly compressed A bypass valve

  12 is used to open the passage, when the pressure is

  maximum permissible pressure in the suction pipe 6 and

  to allow some of the exhaust gas to pass through

  out of the exhaust turbine 11.

  Immediately upstream of the choke valve 7, is placed in the section 6 of the suction pipe,

  an injection valve 14 serving as a feed element

  fuel, by which fuel can be injected immediately before the throttle flap 7, preferably in the opening flap slot

  the first injection valve 14 communicates with a

  fuel supply line 15, in which is

  transported fuel from a fuel tank 18

  by means of a fuel pump 17, driven by an electric motor 16 A pressure regulating valve 19 adjusts the fuel pressure in the fuel supply line In the example

  embodiment, represented by way of example, the installation

  fuel supply, is a fuel injection system, electronic, with a first

  injection valve 14 made in the form of a

  electro-solenoid pope The command of the first

  Injection pump 14 is operated by means of a con-

  control driver 20 by means of a control device

  21 of a known type, depending on the characteristics

  motor operating parameters such as rotation speed 22, air quantity 23, choke valve position 24, temperature 25, pressure in the pipe

  suction 26 in section 6 of this pipe, and others.

  the pressure in the suction pipe in its section 6, between the compressor 5 and the choke flap 7 is determined by means of a pressure sensor 28, connected to the section 6 of the suction pipe,

  whose electrical output signal is sent to the

  control 21 TL'in Jection of fuel by the

  first injection valve 14 upstream of the foreign flap

  This advantage offers the advantage that, thanks to the greater length of the preparation path to the cylinders,

  there is a strengthening of the cooling of the m 6-

  lange and that the filling of the cylinder is improved.

  The compression of the air sucked by the com-

  Presser 5 entrains, in part, air temperatures

  more than 10,000 C, which is, on the one hand, the cause of a

  the cylinder is filled and a lowering of the efficiency ratio of the engine and, on the other hand, carries in itself the danger of a greater wear of the compressor 5 and, consequently, a decrease in its duration. According to the invention, for this reason, a second injection valve 30 serving as a fuel supply element is arranged, also upstream of the compressor 5, in the section 2 of the suction pipe, which is herself

  fueled by a bypass 31 of the

  fuel supply because of the assessment of

  poration of the fuel, injected by the second injection valve 30 upstream of the compressor 5, it is taken from the heat on the sucked air, so that it occurs,

  not only a decrease in the temperature of the com-

  pressure, but also a decrease in the temperature of the air supplied to the cylinders of the engine 4, so that the filling rate of the various cylinders rises, resulting in an increase in the efficiency of the internal combustion engine. due to the turbulence in the compressor, a good distribution of the mixture to the different cylinders occurs. On the other hand, thanks to the injection according to the invention, it is possible to

  remove, or at least reduce, the dimensions of the cooling

  charge air drier than usual the second injection valve 30 can be

  electromagnetic and must be capable of being

  by the electronic control unit 21 Ia

  This second injection valve 30 must be advantageously carried out under conditions such that below the operating temperature.

  of the engine, about 8000, there is no

  by this second injection valve 30, that it

  thus be closed, and that the injection be made exclusively

  By the first injection valve 14 In addition, there is an advantage in idle operating zones.

  Just a little above full non-supercharged

  at the beginning of the overfeed zone of the engine, to suppress injection by the second injection valve 30, and to inject only by the first injection valve 14 only from a little above the full non-supercharged charge,

  ie at the beginning of the overfeed zone

  tion, which, according to the invention, must be

  fuel injection of the first injection valve

  14 to the second injection valve 30, and arrive

  as a result to reinforce the cooling.

  the realization of an injection installation

  fuel injection according to the invention with a first injection valve 14 for injecting fuel upstream of the throttle valve 7, and a second valve

  injection nozzle 30 which injects fuel upstream of the comrn-

  pressure is not limited to the use of a

  Electronic Fuel Injection Instead:

  it is also possible, in a mechanical installation of injection

  fuel injection or in an equivalent embodiment, provide a first and a second injection valve which, under the conditions described, inject fuel

  upstream of the compressor 5 and the choke flap 7.

  The pressure regulator 19 is made, for example, in the form of a diaphragm valve, this

  membrane being made in the form of an elastic septum

  33 separating a control chamber 34 from a chamber

  fuel tank 35, which cooperates with a seat of

  pope 36, placed in the fuel chamber 35, by the

  from which it arrives, depending on the position of the membrane 33, more or less fuel in a return line 37, to then flow by returning to the fuel tank 18 In the control chamber 34,

  is placed a regulation spring 38, which solicits the mem-

  brane 33 in the closing direction of the pressure control valve 19 From the control chamber 34, a pneumatic control conduit leads to an inverting valve 41, the valve spool 42 can

  be operated by an electromagnetic control 43.

  This electromagnetic control 43 can be controlled by the electronic control unit 21 in such a way

  that, during the injection by the first injection valve

  the valve spool 42 is pushed into a position where it connects the pneumatic control line 39 with

  a pressure line 44 of the suction pipe leading to

  section 6 of the suction pipe, between the

  compressor 5 and the choke valve 7 and, when

  This valve slide 42 is actuated by the second injection valve 30 in such a way that the pneumatic control line 39 is connected either to the atmosphere or via a connecting line 45 to the section 2 of the pipe. suction downstream of the air measuring member. Injection reversal, when the motor is at the operating temperature, from the first injection valve 14 to the second injection valve

  30 is advantageously carried out for a particular pressure.

  in the suction pipe, which is obtained slightly above the full supercharged charge, that is to say

  at the beginning of the supercharging zone of the compres-

  5, which is measured by the pressure sensor 28

  in section 6 of the suction pipe between the compres-

  5 and choke 7, which is transmitted to

  the electronic control unit 21.

  FIG. 2 is a graph which shows the quantity of fuel injected Q in the engine, as a function of the load indicated by the pressure p

  suction pipe Above the operating temperature

  motor, it is injected, by the first valve 14, part of the engine idle zone,

  when the load slowly increases, a quantity Q increases

  The pressure Suction pressure Pum determined for switching from the first injection valve 14 to the second injection valve 30 is reached when the first valve is reached. 14 of injection is controlled by the electronic control unit 21, according to a function whose curve is determined in time so that the amount of fuel injected by the first injection valve 14 decreases, according to, for example, the line shown in full line 51, while, according to the same function which extends inversely in time, the second injection valve 30 is controlled by the electronic control unit 21 so as to start the injection and the increasing, according to the line in lines and points 52, upstream of the compressor 5 the sum of the quantities of fuel injected by the first valve 14 and by the second injection valve 30, nt this function

  of transition, must correspond to the quantity of fuel

  necessary, represented by dashed line 53.

  After completion of the transition function determined in time, the injection is carried out only by the second injection valve 30, according to the line

in lines and points 54.

  Correspondingly, the passage of the second injection valve 30 to the first injection valve 14, during a slow decrease in the engine load, must be from an operating point, greater than the pur pressure in the suction pipe, determined, to a lower operating zone to

  the pressure Pu M of the suction pipe, determined

  Jection is done first, when the load drops, until the pressure Pum of the suction pipe, determined by the second injection valve 30, is reached.

line 54.

  With the arrival at the pressure Pum of the pipe

  suction, determined, the control unit 21 elec-

  tronic controls the second injection valve 30

  a transition function in time, so that in the opposite direction of the line 52, the quantity of fuel injected by this second injection valve

  decreases, and conversely, along line 51, the

  Fuel injection by the first injection valve

  14 starts and increases The sum of the quantities of car-

  injected by the injection valves 14, 30 must be

  here correspond to the amount of fuel needed.

  After completion of the transition function, the injection

  only by the first

jection 14.

  FIG. 3 represents, with respect to time t, the curve of the pressure p of the suction pipe

  in section 6, during a sudden

  the operation of the engine, from an operating point lower than the determined pressure, of the suction pipe, and

  higher than the operating temperature of the motor.

  Starting from a pressure pa in the section 6 of the suction pipe, the pressure p of the suction pipe rises when the choke flap 7 is suddenly opened, following

  the curve section 56, first strongly, to reach

  thereafter, substantially in accordance with section 57 of the

  be, non-linear, the determined pum 'pressure, of the suction pipe.

  Figure 4 shows, in a correct way,

  respondent, the increase over time in the quantity

  Q of fuel injected during an accelerating operation

  suddenly from a lower operating point

  at the specified pressure pum of the suction pipe.

  If the Pa pressure in the suction pipe is constant

  it is first injected through the first

  Jection 14, the quantity Qa of fuel If the engine is suddenly accelerated, thus opens the throttle valve 7, the first injection valve 14 is

  ordered, in a known manner in

  Fuel injection, by the control unit 21

  following the curve section 59, enriches

  the fuel-air mixture necessary for accelerating

  If, after a time tur, the determined pressure P u 'of the suction pipe is reached, it follows, according to the switching function already described with reference to FIG. 2, corresponding to the lines 51, 52, the passing from the first injection valve 14 to the second injection valve 30, then the injection by the second injection valve 30 only in an equivalent manner, if the engine load decreases abruptly, from a operating point higher than the pum pressure, determined, the suction pipe, the amount of fuel in Jected by the second valve

  Injection 30 first decreases until

  ture the determined PUM pressure in the vacuum hose

  When this pressure is reached, the injection

  fuel injection by the second injection valve 30 must decrease, according to the time transition functions, in the opposite direction with respect to the lines 51,

  52, and start to increase by the first valve of

  Jection 14 When the transition functions are terminated

  the injection is made only by the first

first injection valve 14.

RBVBNDICAT IONS

  1) Process for forming a mixture for a compression-compression internal combustion engine, comprising a compressor (turbocharger) supplying the suction pipe upstream of a choke flap, and supplying fuel in the suction pipe in

  function of the operating characteristics of this model

  a method characterized in that a first element (14) located immediately upstream of the throttle valve (7) is provided for supplying fuel, and

  a second fuel supply element (30) dis-

  placed immediately upstream of the compressor (5), and that the fuel supply is carried out in zones

  determined the operation of the internal combustion engine

  dull, only by the first (14); in other operating areas of the engine by the first (14), and the second (30) element; and in other areas

  of operation, only by the second element of

fuel (30).

  2) Process according to claim 1, characterized in that, below the temperature of

  operation of the internal combustion engine, the

  fuel is carried out only by means of the

  first element (14) for supplying fuel.

  30) Process according to claim 2,

  characterized in that, after the temperature has been reached,

  engine operation, when the latter

  under a pressiom (pum), determined in

  the suction pipe downstream of the compressor (5), the food

  fuel is made only by means of the

  first element (14) for supplying fuel.

  4) Process according to claim 2,

  characterized in that after the temperature has been reached

  engine operation, during the operation of the

  of this engine above a pressure (pu), de-

  finished, in the suction pipe downstream of the compres-

  (5), the fuel supply is only

  by the second fuel supply element (30).

  Method according to Claim 3, characterized in that if the engine load increases slowly from the moment the pressure is reached

  (pum), determined, in the suction pipe, the food

  fueling by the first fuel element (14).

  fuel consumption decreases according to a specific function

  born (51), and in a way adapted to this function, the

  fuel supply by the second fuel element (30).

fueling begins and increases so that the sum of the fuel quantities supplied by the two feed elements (14, 30) corresponds

  the quantity (53) of fuel required.

  6) Process according to claim 3, characterized in that, if an acceleration is caused

  the engine, from a lower operating point

  in the suction pipe, it is provided by the first element (14)

  fuel supply an increased amount of fuel

  until the pressure is reached (pu M), determined, and that from this pressure (pum) the

  supply of fuel by the first fuel element (14)

  fuel consumption decreases according to a specific function.

  (51), and, in a suitable way, the provision of car-

  by the second feed element (30).

  starting and increasing in such a way that the sum of the fuel quantities provided by the two fuel supply elements (14, 30) corresponding to the

  amount of fuel (53) required.

  7) Process according to claim 4, characterized in that, if the engine load decreases slowly from an operating point higher than the determined pressure (pu M) of the suction pipe,

  supply of fuel by the second fuel element

  fuel (30) decreases from the moment when the pressure (pu), determined, in the

  suction pipe and, in a suitable way, the supply of

  fuel element by the first fueling element (14) starts and increases, so that the sum of the fuel quantities supplied by the

  two elements (14, 30) for supplying fuel

  is responsible for the amount of fuel required.

  8) Process according to claim 4, characterized in that, if the engine load decreases

  suddenly from a higher operating point

  pressure (pum) determined in the pipe

  it is supplied by the second element of

  fuel (30), a reduced amount of fuel until the (pure) pressure is reached,

  determined, and from this pressure (p urm), deter-

  the supply of fuel through the second element (30) decreases and suitably, the supply of fuel by the first fuel supply element (14) begins and increases, so that the sum of the amounts of fuel fuel injected by both

  corresponding fuel supply elements (14, 30)

  from to the amount of fuel needed.

  9) Process according to any one of

  claims 1 to 8, characterized in that, as

  fuel supply (14, 30) is used a fuel injection valve which can be

operated by an electromagnet.

  10) A method according to claim 9, characterized in that the fuel pressure applied to the first fuel injection valve (14) can be adjusted according to the pressure in the suction pipe (p), between the compressor (5) and the throttle valve (7), and that the fuel pressure applied to the second fuel injection valve (30) can

  be set according to the atmospheric pressure.

  11) Installation for supplying fuel to compression-compression internal combustion engines, comprising a compressor (turbo-compressor) supplying the suction pipe, upstream of a throttle valve, the supply of fuel being made in the suction pipe according to characteristics of the operation of the engine, in particular for the execution of the method for forming the mixture according to one of the

  any of claims 1 to 10, a typical installation

  in that it is intended for the supply of

  fuel, a first fuel supply element (14)

  burant placed immediately upstream of the choke

  (7), and a second fuel feed member (30)

  rant, placed immediately upstream of the compressor (5).

  12) Installation according to the claim

  11, characterized by the fact that, below the temperature,

  the internal combustion engine, the fuel supply is carried out only by

  the first fuel supply element (14).

  13) Installation according to the claim

  12, characterized in that, above the temperature,

  the engine, the power supply to the engine

  can be ordered through the first

  (14) and the second (30) fuel feed member

  rant, depending on the pressure (p) in the

  piration, observed downstream of the compressor (5) by a pressure sensor element (28)

  140) Installation according to the claim

  13, characterized in that below a pressure

  (pu), determined, in the suction pipe, the food

  fuel is only made by the first

  (14) fuel supply element.

  0) Installation according to the claim

  13, characterized in that above a pressure

  (pu), determined in the suction pipe, the

  tion is made only by means of the second (30) element

fuel supply.

  16) Apparatus according to claim 14, characterized in that if the load of the engine rises slowly, from the moment when the determined pressure (pua) is reached in the suction pipe, the supply of fuel by the first fuel supply element (14) decreases according to a function (51) determined, and in a suitable manner, the supply

  fueled by the second element (30) begins and

  in such a way that the sum of the quantities of

  provided by the two elements (14, 30) corresponds to

  the amount of fuel (53) required.

  17) Installation according to the claim

  14, characterized in that, if the engine is subjected

  sudden acceleration from a point of operation

  less than the pressure (pure), a high amount of fuel is supplied by the first fuel supply element (14) until the determined pressure (pu) in the pipe is reached.

  suction, and from this pressure (Pum), deter-

  the fuel supply by the first element (14) decreases according to a function (51) determined and, in a suitable way, the supply of fuel by the second element (30) of fuel supply begins and s 'increases, so that the sum of the quantities

  fuel supplied by the two feed elements (14, 30)

  fuel is the amount of fuel

necessary (53).

  18) Installation according to the claim

  15, characterized in that, if the engine load slowly decreases from a point of operation greater than the pressure (pu M), determined, in the pipe

Z 520808

  suction, the supply of fuel by the second supply element (30) decreases, from the moment when the pressure (pum), determined, in the suction pipe, according to a determined function, is reached, and in a suitable manner, the fuel supply by the first element (14) begins and increases, so that the sum of the quantities of fuel supplied

  by the two fuel supply elements (14, 30)

  rant is the amount of fuel required.

  19) Installation according to the claim

  15, characterized in that, if the engine load

  suddenly decreases from a point of operation

  higher than the pressure (pum), determined, in the suction pipe, it is provided by the second element (30) supply a reduced amount of fuel

  Until the pressure is reached (pum), determine

  and, from this pressure (p u), the fuel supply by the second element (30) decreases and, in a suitable manner, the supply of fuel by the

  first element (14) for supplying fuel

  this and increases, so that the sum of the

  fuel tanks provided by both elements (14, 30)

  corresponds to the amount of fuel required.

   ) Installation according to any one

  Claims 11 to 19, characterized in that, as

  fuel supply element (14, 30) is used

  a fuel injection valve that can be action-

born by an electromagnet.

  21) Installation according to claim 20, characterized in that in the fuel supply line (15, 31) which goes to the first (14) and the

  second injection valve (30), there is arranged a

  pressure regulator (19), which regulates the pressure

  the fuel flowing to the first injection valve (14) as a function of the pressure (p) in the suction pipe between the compressor (5) and the throttle flap (7) and the pressure fuel that

  flows to the second injection valve (30) as a function of

atmospheric pressure.

  22) Installation according to claim 21, characterized in that the valve (19) for adjusting the pressure comprises a resilient wall (33) cooperating with a valve seat (36), which is requested, on the one hand, by the fuel pressure in the fuel supply line (15, 31) and on the other hand by an adjusting spring (38) and the pressure existing in a

  pneumatic control line (39).

  23) Installation according to claim 22, characterized in that it is arranged in the pipe

  pneumatic control unit (39), a valve (41) for

  tion-which, controlled by an electromagnet, connects, during the injection by the first injection valve (14), the pneumatic control line (39) with the section (6) of the suction pipe which is located between the compressor (5) and the throttle valve (7), and during injection by the second injection valve (30), connects this

driving with the atmosphere.